Adolph p



(No Model.)

A. F. PRAHM.

' SIGNAL LAMP. No. 886,495. Patented July 24, 1888.

mu inf UNITED STATES PATENT OFFICE.

ADOLPH F. PRAHM, OF INDIANAPOLIS, INDIANA.

SlGNAL-LAMP.

SPECIFICATION forming part of Letters Patent No. 386,495, dated July 24, 1888.

Application filed August 1, 1887. Serial No.245,846. (No model.)

To all whom it may concern.-

Be it known that I, ADOLPII F. PRAHM, of the city of Indianapolis, countyof Marion, and State of Indiana, have invented certain new and useful Improvements in Signal-Lamps, of which the following is a specification.

The object of my invention is to provide efficient ventilation for signal-lamps, such as switch-lamps, carriage-lamps, head-lights,&c., or, indeed, almost any outdoor lamp; and it principally consists in providing horizontal tubes extending through portions of the lampcasing, which are in turn provided with holes for the passage of the air. By this means not only is sufficient ventilation provided, but blasts of air on the flame of the lamp caused by wind are wholly excluded, while the ends of the tubes being open a convenient and effective means of cleaning them by the use of a small brush provided for the purpose may be always at hand.

Referring to the accompanying drawings, which are made a part hereof, and on which similar letters of reference indicate similar parts, Figure 1 is a perspective view of a lamp embodying my said invention, a portion of the casing being broken away to illustrate the invention more perfectly; Fig. 2, a tranverse vertical section of thelamp, and Fig. 3 a horizontal sectional view looking downwardly from the dotted line 3 3 in Fig. 2.

In said drawings, the portions marked A represent the casing of the lamp; B. the glasses to the lamp used in signaling; 0 C, the ventilating-tubes, and I) the door to the lamp.

The casing A is in general form not dissimilar to lamps already in use, being preferably a sheet'inetal cylindrical casing with a reduced top, as shown. Holes are formed therein to receive the ventilating-tubes. Upon one side is attached a casting, A, having flanges to receive the door. The bottom is preferably formed of another casting, A", which not only supports that portion of the lamp A which contains theilluminating-fluid, butis also provided with a socket, a, by which it may be secured upon the standard of the switch, or to whatever it is to be attached.

The glasses B, for switclrlamp purposes, are preferably, as shown, and as usual, four in number, two of which are white and two red, as will be readily understood by those familiar with such matters. They are located in opposite sides of the lamp-easing, as usual, and

as shown, the two of a corresponding color facing each other.

The ventilating-tubes C extend in both directions through the reduced top of the lampcasing, and are provided inside said casing with numerous orifices, through which the hot air from the interior of the lamp will escape. As they run in both'directions, and as they are of equal diameter throughout, wind, when it enters them, will pass directly through with out affecting the blaze of the lamp, and when the openings get clogged with soot, as is frequently the case, asmall cylindrical brush can be passed through them, and they can thus be cleaned quickly and effectually. Corresponding tubes, 0, pass through the lower part of the lamp structure, and are similarly provided with holes for the admission of air to the lamp,

all as will be readily understood.

The door D to the lamp is a plain slide-door formed of sheet metal, having flanges which engage with the flanges on the casting A on one side of the lamp. Its center contains one of the glasses B. Asliding door having flanges which engage with slots or grooves is much superior for this purpose to a door hung on hinges, as the latter frequently works loose and admits the wind or storm, which impairs or extinguishes the light, while a door formed as shown is always, when closed, perfectly tight, preventing any such result.

Having thus fully described my said invention, what I claim as new, and desire to secure by Letters Patent, is-- 1. The combination, with a lantern-body, of ventilatortubes arranged horizontally within said body, said tubes being open at their ends to the outer air and having perforated walls, substantially as set forth.

2. The combination, in a lantern, with the casing thereof, of ventilator-tubes arranged horizontally within said casing. a part of which cross the others, the ends of said tubes being open to the outer air and their walls being perforated, substantia ily as described, and for the purposes specified.

In witness whereof I have hereunto set my hand and seal, at Indianapolis, Indiana, this 27th day of July, A. D. 1887.

ADOLPH F. PRAHM. [n 8.]

In presence of- C. BRADFORD, WM. GARSTANY. 

